Prediction Markets API

io.github.Br0ski777Published by GitHub account Br0ski777v1.1.0Updated Oct 24, 2026

Prediction market odds from Polymarket. Active markets, probabilities, volume. x402.

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Overview

AI-generated overview

Remote MCP server that gives an assistant live Polymarket and Kalshi prediction-market odds, probabilities and volume, paid per call in USDC via x402.

What you can do
  • List active prediction markets with odds, volume, liquidity and categories, filtered by topic or platform and sorted by volume, newest or closing soon
  • Look up detailed odds and trading data for one market by ID or question text, including 24h volume and resolution criteria
  • See trending markets ranked by recent volume and activity, with 24h probability change
When to use it
Useful when an assistant needs current implied probabilities on real-world events — elections, crypto milestones, macro outcomes — for forecasting, research or commentary, rather than raw asset prices.
Requirements
Remote SSE endpoint at prediction-markets.api.klymax402.com; no API key or signup. Each call is paid per request in USDC on Base L2 through the x402 protocol, so the client needs an x402-aware wallet or payment handler that can answer a 402 challenge and retry.
Before you install
Every tool call costs money (roughly $0.008–$0.012 per call in USDC on Base), so an agent can spend funds without a separate confirmation step. Payment requires a funded wallet and signing x402 challenges; the service relies on third-party facilitators (Coinbase CDP, PayAI) and forwards queries to Polymarket and Kalshi data. Odds are informational, not trading advice.

Installation

In SourceWeft

  1. Open Prediction Markets API in the dashboard and add it to a workspace.
  2. Enable the server for the chats that should use its tools.

Web executable via SSE. Remote servers run from the web runtime once configured in a workspace.

Use with an agent

Paste this prompt into Claude Code, Codex, Cursor or another agent — or into SourceWeft chat. The agent reads this server's install guide, shows you its publisher, endpoint and sign-in, and adds it to your client once you agree. Keys never go into a command.

Read https://sourceweft.com/mcp/io.github.Br0ski777%2Fprediction-markets/install.md and connect the MCP server it describes to my client. Before changing any config, show me its publisher, endpoint and sign-in method and wait for my OK. Never put an API key in a command or in a file I would commit; ask me where it should come from.

Read the install guide the agent follows

Other MCP clients

Add this to your client's mcpServers config.

{
  "mcpServers": {
    "prediction-markets-api": {
      "type": "sse",
      "url": "https://prediction-markets.api.klymax402.com/mcp"
    }
  }
}

README

Prediction Markets API

[MCP Server] [x402] [License: MIT]

Real-time prediction market odds from Polymarket and Kalshi. Active markets, probabilities, volume, categories. The betting intelligence layer agents need for event forecasting. Pay-per-call via x402 (USDC on Base L2) -- no API key, no signup, no rate-limit wall.

Part of the klymax402 marketplace -- 100 x402 micropayment APIs for AI agents, one wallet, USDC on Base.

Quickstart -- MCP

Add to your MCP client config (Claude Desktop, Cursor, ElizaOS, etc.):

json
{  "mcpServers": {    "prediction-markets": {      "url": "https://prediction-markets.api.klymax402.com/mcp"    }  }}

Quickstart -- HTTP (x402)

bash
curl -X POST "https://prediction-markets.api.klymax402.com/api/markets" \  -H "Content-Type: application/json" \  -d '{}'# -> 402 Payment Required, with an x402 payment challenge in the response body

Any x402-aware client (@x402/fetch, x402-agent-tools, ATXP) handles the 402 -> sign -> retry cycle automatically.

Tools

ToolMethodPathPriceDescription
prediction_list_marketsPOST/api/markets$0.012List active prediction markets from Polymarket and Kalshi with current odds, volume, and categories. Filter by topic, platform, and sort by volume, newest, or closing soon.
prediction_get_market_oddsPOST/api/odds$0.012Get detailed odds and trading data for a specific prediction market by ID or search query. Searches both Polymarket and Kalshi.
prediction_trending_marketsPOST/api/trending$0.008Top trending prediction markets from Polymarket and Kalshi ranked by volume and engagement.

prediction_list_markets

Use this when you need to browse active prediction markets or find betting odds on real-world events. Returns a list of active markets from Polymarket and Kalshi with current probabilities, trading volume, and metadata.

Parameters

NameTypeRequiredDescription
categorystringnoFilter markets by topic category. Omit for all categories.
limitnumbernoNumber of markets to return (1-50). Default: 20.
sortstringnoSort order. 'volume' = highest traded, 'newest' = recently created, 'closing_soon' = ending soonest. Default: volume.
sourcestringnoFilter by platform. Omit to get markets from both Polymarket and Kalshi.

Returns

  • question -- the prediction market question (e.g. "Will Bitcoin reach $100k by December 2026?")
  • outcomePrices -- probability for each outcome as decimal (0.65 = 65% chance YES)
  • volume -- total trading volume in USD
  • liquidity -- current available liquidity in USD
  • endDate -- when the market resolves
  • category -- topic category (politics, crypto, sports, science, culture)
  • active -- whether the market is currently trading
  • source -- data source -- "polymarket" or "kalshi"

Example response:

json
{ markets: [{ question: "Will Trump win 2028?", outcomePrices: { "Yes": 0.42, "No": 0.58 }, volume: 15420000, liquidity: 890000, endDate: "2028-11-06", category: "politics", source: "polymarket" }] }

Not for: crypto price data (use token_get_price), crypto news (use crypto_get_news), stock prices (use stock_get_quote), DeFi yields (use defi_find_best_yields), Hyperliquid perp data (use hyperliquid_get_market_data).

prediction_get_market_odds

Use this when you need detailed odds, probabilities, and trading data for a specific prediction market. Searches both Polymarket and Kalshi to find the best match by market ID or question text.

Parameters

NameTypeRequiredDescription
marketIdstringnoPolymarket condition ID or Kalshi ticker. Use this if you already know the market ID.
querystringnoSearch query to find a market by question text (e.g. 'bitcoin 100k', 'trump election'). Used when marketId is not known.

Returns

  • question -- the full prediction market question text
  • outcomes -- array of possible outcomes with their current probabilities
  • outcomePrices -- decimal probabilities per outcome (0.72 = 72% implied probability)
  • volume -- total all-time trading volume in USD
  • volume24h -- trading volume in the last 24 hours
  • liquidity -- current depth of the order book in USD
  • endDate -- resolution date of the market
  • description -- detailed market description and resolution criteria
  • active -- whether the market is currently open for trading
  • source -- which platform the market is from -- "polymarket" or "kalshi"

Example response:

json
{ question: "Will ETH flip BTC by 2027?", outcomes: ["Yes", "No"], outcomePrices: { "Yes": 0.08, "No": 0.92 }, volume: 2340000, volume24h: 45000, liquidity: 120000, endDate: "2027-12-31", active: true, source: "polymarket" }

Not for: crypto price data (use token_get_price), crypto news (use crypto_get_news), stock prices (use stock_get_quote), DeFi yields (use defi_find_best_yields), Hyperliquid perp data (use hyperliquid_get_market_data).

prediction_trending_markets

Use this when you need to see what prediction markets are trending right now. Returns the hottest markets from both Polymarket and Kalshi ranked by recent trading volume and activity.

Parameters

NameTypeRequiredDescription
limitnumbernoNumber of trending markets to return (1-30). Default: 10.
sourcestringnoFilter by platform. Omit to get trending markets from both Polymarket and Kalshi.

Returns

  • question -- the market question
  • probability -- current implied probability for the leading outcome (decimal)
  • volume24h -- trading volume in the last 24 hours in USD
  • totalVolume -- all-time trading volume in USD
  • priceChange24h -- change in probability over the last 24 hours (e.g. +0.05 = probability rose 5%)
  • category -- topic category
  • endDate -- when the market resolves
  • source -- data source -- "polymarket" or "kalshi"

Example response:

json
{ trending: [{ question: "Will Fed cut rates in July 2026?", probability: 0.73, volume24h: 890000, totalVolume: 12500000, priceChange24h: 0.08, category: "politics", endDate: "2026-07-31", source: "polymarket" }] }

Not for: crypto price data (use token_get_price), crypto news (use crypto_get_news), stock prices (use stock_get_quote), DeFi yields (use defi_find_best_yields), Hyperliquid perp data (use hyperliquid_get_market_data).

Example agent prompts

  • "Browse active prediction markets or find betting odds on real-world events"
  • "Detailed odds, probabilities, and trading data for a specific prediction market"
  • "See what prediction markets are trending right now"

Payment

  • Protocol: x402 -- HTTP-native pay-per-call, no signup, no API key
  • Network: Base L2 (eip155:8453)
  • Asset: USDC
  • Facilitator: Coinbase CDP (primary), PayAI (fallback)
  • Also reachable via ATXP (OAuth-wrapped x402, RFC 9728 protected-resource metadata)

Part of klymax402

100 x402 micropayment APIs for AI agents -- one wallet, USDC on Base, zero signup.

License

MIT

Source: README.md at commit c8aa4d5

Tools

0
SourceWeft has not read this server's tools yet.

Version history

1
  1. v1.1.0LatestSep 16, 2026

Score

50% of the applicable checks met

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  • Reached in the last 30 daysRequired25 pts

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  • Auth declaredRequired10 pts

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  • Tools listed15 pts

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